$upport your local store, until....

[beren]

I've spent time around lots of pressurized tanks. Scuba, propane, CO2, paintball, compressors. Never heard of one failing. Leaking, sure. Boom, no.
Did yours just pop something internal or actually fail externally somehow? Did you trash it or was it capable of refurb? I guess you'd never trust it again after something like that - even if it could be rebuilt.
Just curious.

My dad has gotten tanks refilled at truck stops where they filled it until the overflow vented. They still held gas just fine. It sounds like something internal really failed hard if the entire propane tank vented.

Co2 tanks have a burst disk which is different and will let the tank empty.

 

[Broothru]

My dad has gotten tanks refilled at truck stops where they filled it until the overflow vented. They still held gas just fine. It sounds like something internal really failed hard if the entire propane tank vented.

Co2 tanks have a burst disk which is different and will let the tank empty.

There’s a bleeder valve on the fill device, or sometimes plumbed in to the tank fill line like on my RV, that can be used to determine the fill of a tank. When it stops bleeding gaseous fluid and starts venting liquid, you’re pretty much as full as you’re gonna’ get.

 

[shoengine]

Everything I am reading about propane (https://duckduckgo.com/?q=how+full+can+propane+tanks+be+filled&t=vivaldim&ia=web) is that you start with the nominal size of the tank (eg. 20lb) and multiply by 0.8 to get the total filled capacity. Of course these are all coming from suppliers, but I'm not sure why any other source would matter more.

I'm having a harder time finding info on CO2, but at least one place says 34% of capacity (https://www.kegerators.com/articles/CO2-Tank-Guide/), while a Federal guide for shipping maxes out around 70% (https://www.ecfr.gov/current/title-49/subtitle-B/chapter-I/subchapter-C/part-173/subpart-G)

Is there a hard and fast rule for refilling or exchanges? For propane it seems 80%, but temperature can play a role. I think that all propane tanks are steel, but with CO2 aluminum is quite common. Should an aluminum tank be filled to the same density as a steel tank? I assume the relief systems on an aluminum tank will be set to a lower pressure than that of a steel tank. My takeaway is that none of these tanks are ever going to be filled to 100% of their volume.

 

[Bobby_M]

https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.2200-01.pdf

 

[beren]

Everything I am reading about propane (https://duckduckgo.com/?q=how+full+can+propane+tanks+be+filled&t=vivaldim&ia=web) is that you start with the nominal size of the tank (eg. 20lb) and multiply by 0.8 to get the total filled capacity. Of course these are all coming from suppliers, but I'm not sure why any other source would matter more.

I'm having a harder time finding info on CO2, but at least one place says 34% of capacity (https://www.kegerators.com/articles/CO2-Tank-Guide/), while a Federal guide for shipping maxes out around 70% (https://www.ecfr.gov/current/title-49/subtitle-B/chapter-I/subchapter-C/part-173/subpart-G)

Is there a hard and fast rule for refilling or exchanges? For propane it seems 80%, but temperature can play a role. I think that all propane tanks are steel, but with CO2 aluminum is quite common. Should an aluminum tank be filled to the same density as a steel tank? I assume the relief systems on an aluminum tank will be set to a lower pressure than that of a steel tank. My takeaway is that none of these tanks are ever going to be filled to 100% of their volume.

There is so much bad information online that seems identical and written by ai. A tank size in pounds is how much the tank can safely hold. A total size in gallons is the real size of the tank and you can put 20% less in. So a 500 gal tank can hold 400gal of liquid propane. A 50lb propane tank can hold 50lb of propane safely.

https://www.amerigas.com/about-propane/propane-tank-sizes

 

[shoengine]

There is so much bad information online that seems identical and written by ai. A tank size in pounds is how much the tank can safely hold. A total size in gallons is the real size of the tank and you can put 20% less in. So a 500 gal tank can hold 400gal of liquid propane. A 50lb propane tank can hold 50lb of propane safely.

https://www.amerigas.com/about-propane/propane-tank-sizes

Kind of a throw-away reply there.

 

[beren]

Kind of a throw-away reply there.

Not really. If the tank is sized in pounds, that’s what you put in if it’s sized in gallons you put in 20% less.

This link makes it clearer: https://www.amerigas.com/commercial-propane/propane-tank-sizes

 

[mac_1103]

My totally non-expert WAG is that big propane exchangers like Blue Rhino are intentionally underfilling to give themselves a little extra speed (for $) and margin of error (for liability). If you do a bit of digging, they do tell you that you're only getting 15 lbs in a 20 lb exchange tank, so it's not exactly a rip-off, but they certainly could make that information easier to find.

 

[Bobby_M]

My totally non-expert WAG is that big propane exchangers like Blue Rhino are intentionally underfilling to give themselves a little extra speed (for $) and margin of error (for liability). If you do a bit of digging, they do tell you that you're only getting 15 lbs in a 20 lb exchange tank, so it's not exactly a rip-off, but they certainly could make that information easier to find.

The entire class action lawsuit was predicated on the lack of transparency. People thought they were still getting the totally safe and customary 20 pound fills but they weren't. The labels now say 15lb net weight and that was not their choice to do it.

 

[mac_1103]

The entire class action lawsuit was predicated on the lack of transparency. People thought they were still getting the totally safe and customary 20 pound fills but they weren't. The labels now say 15lb net weight and that was not their choice to do it.

Thanks. ISTM that some people still think they're getting 20 lbs.